Democratic and Republican primaries are held Tuesday in Alabama, Arkansas, Georgia, Massachusetts, Minnesota, Oklahoma, Tennessee, Texas, Vermont and Virginia. Alaska is also holding its Republican caucus while Colorado holds its Democratic caucus on Tuesday. In total, 865 Democratic delegates and 595 Republican delegates are up for grabs on Tuesday. Most of the polls are expected to be closed by 8 p.m. ET/4 p.m. PT.

Clinton heads into Super Tuesday in the lead against Sanders, after she has won three out of four Democratic contests so far in Nevada, South Carolina and Iowa. Trump has pulled way ahead in the GOP race, decisively winning in Nevada, South Carolina and New Hampshire, with an expected win Tuesday.

Here is a roundup of significant events, updated throughout the night.

Donald Trump Wins Vermont for Total of 7 States

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Updated 9:05 p.m. PT:

Donald Trump has now won a total of seven states on Super Tuesday, adding Vermont to his tally late Tuesday night, according to the AP. The GOP candidate has pulled way ahead his opponents, with Ted Cruz still counting only two states and Marco Rubio only one.

Donald Trump has added his sixth win for Super Tuesday with Arkansas, the AP has reported. Trump is now way ahead of his GOP opponents. Ted Cruz counts two victories with Texas and Oklahoma, and Marco Rubio, John Kasich and Ben Carson still have none.

Trump has been declared the winner of Georgia's Republican primary on Super Tuesday, reported The Associated Press. This is his first victory of the day, beating out Ted Cruz, Marco Rubio, John Kasich and Ben Carson in the southern state.

Hillary Clinton Wins Massachusetts & 6 Southern States

Updated 8:35 p.m. PT:

Hillary Clinton has won Massachusetts, bringing her total on Super Tuesday to seven states against Bernie Sanders' four (Minnesota, Colorado, Oklahoma and Vermont). Clinton has so far been dominating the southern states, also taking Texas, Arkansas, Alabama, Tennessee, Georgia and Virginia.

Clinton has added Arkansas to her wins for a total of five states (Arkansas, Alabama, Tennessee, Georgia and Virginia). Her opponent Bernie Sanders currently has won one, his home state of Vermont. Clinton tweeted out a heartfelt message, "A win especially close to Hillary’s heart," to her supporters in Arkansas, where her husband Bill was governor.

Clinton continues her sweep throughout the southern states, winning Alabama and Tennessee on Super Tuesday. Earlier today, Clinton was declared the winner in Georgia and Virginia, making her total victories four states against Bernie Sanders' one (Vermont).

Bernie Sanders Takes Minnesota, Colorado, Oklahoma

Updated 8:30 p.m. PT:

Bernie Sanders is pulling ahead in the Democratic race on Super Tuesday, now winning a total of four states: Minnesota, Colorado, Oklahoma and Vermont, according to the AP. Hillary Clinton currently has won six states (Texas, Arkansas, Alabama, Tennessee, Georgia and Virginia).

Sanders has added Colorado to his list of victories on Super Tuesday, bringing his total count to three states (Colorado, Oklahoma, Vermont). Sanders tweeted about his victory Tuesday night, welcoming Colorado voters "to the political revolution."

Sanders has been declared the winner of the Democratic primary in Oklahoma, The Associated Press reports. This is his second win of the day against Hillary Clinton, adding to his victory in his home state of Vermont.

Marco Rubio Wins Minnesota

8:35 p.m. PT:

GOP candidate Marco Rubio has taken Minnesota, his first win of Super Tuesday. So far, Donald Trump has dominated the Republican field on Tuesday with six states, with Ted Cruz coming in second with two. John Kasich and Ben Carson have yet to make a showing.

Trump Turns Victory Speech Into Q&A

7:35 p.m. PT:

For the most part, Donald Trump was gracious and humble while talking about his Super Tuesday victories. Still, he did take digs at Hillary Clinton and Marco Rubio, but nothing compared to the harsh rhetoric from the past week on the campaign trail.

"Make America great again is going to be much better than making America 'whole’ again," he said, referring to Clinton's earlier remarks.

Sticking closely to his stump messages, Trump even took a few questions from reporters at the event, turning his victory speech into a press conference that he held in front of a gaudy presentation at his Palm Beach, Fla., headquarters.

Trump congratulated Ted Cruz on winning his home state of Texas. He then thanked his family and supporters.

After telling the crowd that the Republican party needs to unite to "make sure that Hillary Clinton never gets back into the White House,” Christie referred to Trump as “a bold, tough and decisive leader.” He then called Trump to the stage as "the next president of the United States."

Ted Cruz Wins Two States, Calls for United GOP

Updated 7:15 p.m. PT:

Ted Cruz spoke to his supporters in Stafford, Texas, on Tuesday night, after winning two states to Donald Trump's five. The GOP candidate focused on uniting the Republican party behind him, welcoming supporters of other candidates like Jeb Bush, who has dropped out, in order to come together and beat Trump for the Republican nomination.

"So long as the field remains divided, Donald Trump's path to the nomination remains more likely," said Cruz, "and that would be a disaster."

"We are the only campaign that has beaten Donald Trump once... twice... three times!" he added, calling the billionaire mogul "profane and vulgar."

Cruz has won Oklahoma and his home state of Texas in Tuesday's GOP primaries, according to The Associated Press. These are Cruz's first two victories of the day, with Donald Trump taking the rest of the states reporting so far.

Major News Networks React to Big Wins By Trump, Clinton

As wins came pouring in for Donald Trump, much of the TV media coverage focused once again on how a Trump candidacy would dismantle the Republican party.

“This is a hostile takeover of the Republican party and they should have seen it coming,” observed Bret Baier, Fox News' chief political anchor. The network then cut to chief political correspondent Carl Cameron at the Trump headquarters at the Mar-a-Lago Club in Palm Beach, Fla., who likened the room for Trump's press conference to the Palace of Versailles, “with the chandeliers and the gilt.”

Around 9:15 p.m. ET when news networks began to project Oklahoma for Ted Cruz, the narrative shifted to the battle between Cruz and Rubio.

CNN’s John Kingg noted that “Cruz will be able to make the case mathematically” that Rubio should get out of the race.

“Let’s be honest,” said Fox News’ Baier, “There could be a push by Cruz for Marco Rubio to leave to race.”

“I think we can expect that,” his co-anchor Megyn Kelly replied.

Meanwhile, Democratic frontrunner Hillary Clinton was busy racking up delegates while Bernie Sanders made his Vermont victory speech at 7:30 p.m., which CNN’s Jake Tapper noted was awfully early in the evening for a victory speech. To which his colleague Dana Bash pointed out that it would likely be Sanders only chance to make such a speech this evening. >>Read More

Hillary Clinton: "America Never Stopped Being Great"

6 p.m. PT:

After winning five states on Super Tuesday (and just before her win in Texas was announced), Hillary Clinton addressed her supporters in Miami, including a reference of GOP frontrunner Donald Trump's slogan of "Make America Great Again!"

"We know we’ve got work to do," Clinton said. "It's not to make America great again — America never stopped being great. We have to make America whole."

Sanders: "We Cannot Allow the Donald Trumps of the World to Divide Us Up"

4:45 p.m. PT:

Bernie Sanders took a shot at Donald Trump while giving an early evening victory speech in his home state.

"We cannot allow the Donald Trumps of the world to divide us up," he told a cheering crowd at Sanders' headquarters in Vermont. He continued, "When we bring our people together and stand up to the billionaire class and tell them — They can’t have it all. That our government belongs to all of us, not just the super-PACs and wealthy campaign contributors."

He also took aim at the Republican candidates in general when talking about climate change, saying they "think that climate change is a hoax. Well I believe that you don’t develop real public policy unless you listen to the science and the science is clear."

He then had a message for Hillary Clinton: "I know that Secretary Clinton and many of the establishment people think that I am looking and thinking too big — I don’t think so."